The invention relates to a universal qrinder having a bed on which a workpiece spindle head, a qrindinq spindle head and a footstock are arranged.
Universal grinders of the initially mentioned type are used for machining round surfaces on the interior side or exterior side of workpieces as well as for machining plane surfaces on workpieces. They are produced in very different sizes for the manufacturing of individual parts as well as for the manufacturing of large series of workpieces. The grinding operations on the corresponding workpieces are carried out by means of an abrasive disk or abrasive belt. Since workpieces occur in practice which vary considerably in their dimensions and, for example, in their length and in the diameter may deviate at a ratio of more than 1:100, very different universal grinders must be created. This is necessary also because the ratio of the length to the diameter may also vary to an extreme extent; i.e., in one case, long and thin workpieces, and in the next case, short plate-shaped workpieces may have to be machined. In this situation, it is customary during the machining of workpiece having a great length, such as a marine propeller shaft, to design the universal grinder such that the rotating axis of the workpiece extends horizontally, in which case, the mounting lengths of the workpiece may measure up to several meters. Disk-shaped and plate-shaped workpieces may be aligned and gripped more easily if the workpiece can be placed and mounted on a horizontal table which rotates around a vertical shaft. Because of the large number of the different workpieces to be machined, a large number of different types of universal grinders is obtained. This results in considerable investments for shops, particularly for repair shops which must carry out very different work on very different workpieces and machine only a relatively small number of these workpieces at a time.
In order to carry out the machining of differently shaped workpieces by means of a convertible machine, it is known (DE-AS 19 37 300) to assemble the substructure of this machine of several box-shaped base elements which, mutually exchangeably, can be connected with one another in different forms by means of detachable connections.
An object of the invention is to provide a universal grinder of the initially mentioned type which is adaptable over wide ranges to the dimensions of very different workpieces, while optimal working conditions are maintained.
This object is achieved in that the workpiece spindle head, the grinding spindle head and the footstock are each constructed as separate constructional units which are fixed to the substructure by means of fixing devices which permit a detaching and a changing of the relative working positions and a reattaching in the new working positions.
By means of this construction, in which the constructional units are connected only by means of mechanical, electrical or hydraulic control transmitting devices, a change-over to another workpiece can be carried out within a very short period of time. This type of a universal grinder is particularly suitable for a repair shop in which workpieces must be machined which have very different dimensions, in each case only one or only a few workpieces having to be machined.
In a further development of the invention, it is provided that the bed is constructed as a plate having a plane top surface on which the constructional units can be displaced and gripped. As a result, it becomes possible in a very simple manner to precisely align the individual constructional units with respect to one another since the plane top surface of the plate may be used as a reference plane.
In order to facilitate the aligning of the constructional units in certain preferred embodiments, it is provided that the constructional units are equipped with identification generators which are mounted at respectively defined points and can be recognized by an adjusting device.
A simple and secure gripping of the constructional units at the bed is obtained in that, in a further development of preferred embodiments of the invention, the constructional units are each equipped with an electromagnetic gripping device which braces them with respect to the bed.
In order to facilitate the displacing of the constructional units, it is provided in a further development of preferred embodiments of the invention that the constructional units are each equipped with a lift-off device which permits a detaching from the bed. This lift-off device may also be connected with a sliding device or other device which reduces the displacing resistance of the constructional units.
In a further development of preferred embodiments of the invention, devices are-provided for storing the relative working positions of at least the workpiece spindle head and the grinding spindle head which are suitable for the machining of certain workpieces. As a result, it becomes possible to very easily retrieve the working positions which had already been taken up once for the machining of a corresponding workpiece.
In a further development of preferred embodiments of the invention, it is provided that the workpiece spindle head and/or the grinding spindle head are each provided with a mounting surface which extends transversely to the spindle shaft and a mounting surface which extends parallel to the spindle shaft for the mounting on the bed. As a result, the workpiece spindle head and/or the grinding spindle head can be arranged in different positions on the bed, for example, with a vertical spindle shaft or a horizontal shaft so that an adaptation is possible also in this respect to the type of workpiece to be machined.
For the same purpose, it is provided in another development of the invention that at least two different types of workpiece spindle heads and/or grinding spindle heads are provided. The most suitable constructional unit for that particular application may then be used in each case.
In a further embodiment of the invention, it is provided that the workpiece spindle head and/or the grinding spindle head and/or the footstock each have a bottom part, which can be mounted on the bed, and a top part, which is adjustable with respect to the bottom part. In this embodiment, it is possible to carry out a relatively rough adjusting of the new working positions by connecting the bottom parts with the bed, while the precise adjusting will then take place by the relative adjustment of the respective top parts with respect to the bottom parts.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.